Hexacarboxyl binuclear metal iron phthalocyanine catalyst as well as preparation method and application thereof
The hexacarboxyl binuclear metal phthalocyanine iron catalyst prepared by phthalanhydride-urea melting method is combined with the permonosulfate system, which solves the problem of low degradation efficiency of stubborn pollutants in the water environment, and achieves efficient degradation and anti-interference performance, so the catalyst is easy to Recycle.
Patent Information
- Application Number
- CN202411241234.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-05
- Publication Date
- 2024-12-17
AI Technical Summary
The prior art is difficult to efficiently degrade refractory and non-biodegradable pollutants in water environments, especially under the influence of natural organic matter and inorganic anions in water, the efficiency of the catalyst is low.
The hexacarboxyl binuclear metal phthalocyanine iron catalyst was prepared by phthalic anhydride-urea melting method, expand its π conjugation system, improve catalytic activity, and combine it with the permonosulfate system to degrade pollutants by producing high-valent metal oxygen species.
The 99% degradation rate of levofloxacin pollutants was achieved, and the efficient catalytic performance was maintained under the interference of inorganic anions and organic matter in water, and the catalyst was easy to recover.
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Figure CN119143766A_ABST
Abstract
Description
Technical Field
[0001] The invention belongs to the technical field of metal phthalocyanine iron catalyst and water environment pollutant degradation, and specifically relates to a hexacarboxyl binuclear metal phthalocyanine iron catalyst and a preparation method and application thereof. Background Art
[0002] Due to the need to treat wastewater containing stubborn and non-biodegradable pollutants, in recent years, persulfate-based advanced oxidation technology (AOPs) has attracted widespread attention due to its excellent removal efficiency, rapid operation and versatility for a variety of pollutants. The degradation of pollutants depends on the generation of reactive oxygen species. Compared with free radical systems, non-free radical systems can resist the influence of natural organic matter and inorganic anions in water well, and have a good treatment effect in actual wastewater. High-valent metal oxygen species have the characteristics of high spin state, high reduction potential, long life and oxidation and degradation of organic pollutants in a wide pH range. Advanced oxidation technology based on the generation of high-valent metal oxygen species is a very promising technology.
[0003] Phthalocyanine is a class of porphyrin-like macrocyclic compounds with conjugated large π bonds, with a relatively uniform distribution of electron density and a very stable phthalocyanine ring structure. Different structures and substituents will affect the properties of phthalocyanine. Therefore, related monomeric phthalocyanine complexes are particularly attractive oxidation catalysts. Planar binuclear phthalocyanine is a new type of phthalocyanine compound connected by phthalocyanine monomers. Two phthalocyanine units share a benzene ring. It has two metal centers, an expanded conjugated system, and the active center of π electrons is twice that of mononuclear phthalocyanine. Its synergistic effect and the expanded π conjugated system make the catalytic activity of binuclear metal phthalocyanine significantly higher than that of the corresponding mononuclear metal phthalocyanine.
[0004] Based on the above analysis, the present invention adopts the phthalic anhydride-urea melting method to prepare hexacarboxyl binuclear phthalocyanine iron to obtain a planar shared benzene ring binuclear phthalocyanine. Under room temperature conditions, it has a good efficiency in degrading organic pollutants and is not affected by inorganic anions and natural organic matter in water. There is no relevant report in this regard. Summary of the invention
[0005] The technical problem solved by the present invention is to provide a hexacarboxy binuclear metal phthalocyanine iron catalyst with high catalytic efficiency, good practical application effect and easy recovery, and a preparation method thereof. The hexacarboxy binuclear metal phthalocyanine iron catalyst prepared by the method can be used to activate peroxymonosulfate to degrade levofloxacin (LVF) pollutants in water environments.
[0006] The present invention adopts the following technical solution to solve the above technical problems, a method for preparing a hexacarboxyl binuclear metal phthalocyanine iron catalyst, characterized in that the specific process is: Step S1, preparation of hexacarboxamide binuclear phthalocyanine iron: trimellitic anhydride, pyromellitic anhydride, urea, ferrous chloride and catalyst ammonium molybdate tetrahydrate are ground and mixed evenly, and then the mixture is heated to 140-150° C. and reacted at a constant temperature for 20-40 min, and then the mixture is heated to 200-210° C. and reacted at a constant temperature for 3-5 h. After the reaction is completed, the mixture is cooled to room temperature, and the product is ground into fine powder to obtain hexacarboxamide binuclear phthalocyanine iron; Step S2, preparation of hexacarboxyl binuclear phthalocyanine iron: adding the hexacarboxyl amide binuclear phthalocyanine iron obtained in step S1 into a reaction container, then adding NaOH solution and stirring and refluxing the reaction, adding ultrapure water to dilute after the reaction is completed, centrifuging, taking the supernatant and adjusting the pH to 1-2 with concentrated hydrochloric acid to produce phthalocyanine iron floccules, and standing the phthalocyanine iron to precipitate to obtain hexacarboxyl binuclear phthalocyanine iron.
[0007] The preparation method of the hexacarboxyl binuclear metal phthalocyanine iron catalyst of the present invention is characterized by the following specific steps: Step S1, preparation of hexacarboxamide binuclear phthalocyanine iron: weigh 5.76g of trimellitic anhydride, 1.09g of pyromellitic anhydride, 18g of urea, 2.18g of ferrous chloride and 0.27g of catalyst ammonium molybdate tetrahydrate, grind and mix them evenly in a mortar and transfer them to a 100mL crucible, place the crucible in a 250mL glass beaker to prevent the ammonia generated during the reaction from splashing the raw materials, and then place the crucible in a muffle furnace for heating reaction. The heating reaction process adopts a two-stage heating method. First, the temperature is raised to 145°C within 40min, the crucible is taken out and shaken to mix the materials evenly, and then placed in a muffle furnace for constant temperature reaction at 145°C 30min, then raise the temperature to 200℃ within 55min and react at a constant temperature for 4h. After the reaction is completed, cool to room temperature, grind the product in an agate mortar to obtain a solid powder, add the solid powder into a 250mL three-necked round-bottom flask, add ultrapure water, heat and reflux at 100℃ in an oil bath for 1h, centrifuge the mixture to remove the supernatant, wash twice with ultrapure water, then wash twice with 2wt% hydrochloric acid solution in the same process, wash with ultrapure water until neutral, finally wash twice with acetone and anhydrous ethanol according to the above operation, then place in a vacuum drying oven for 12h, and grind with an agate mortar to obtain hexamethylamide binuclear phthalocyanine iron after cooling; Step S2, preparation of hexacarboxyl binuclear phthalocyanine iron: add the hexacarboxamide binuclear phthalocyanine iron obtained in step S1 to a 250mL three-necked flask, then add 100mL of 2mol / L NaOH solution, and reflux under magnetic stirring in an oil bath for 12h. After the reaction, add 5 times of ultrapure water for dilution, centrifuge, take the supernatant, adjust the pH to 1-2 with concentrated hydrochloric acid solution to produce phthalocyanine iron floccules, let stand for 12h to precipitate the phthalocyanine iron, pour out the upper clear liquid, centrifuge the lower material, and continuously wash with ultrapure water until neutral during the centrifugation process. Wash with methanol, acetone and anhydrous ethanol in the same operation, repeat three times, and finally place it in a vacuum drying oven at 80°C for 10h, take out the sample after cooling to room temperature, and grind it evenly in an agate mortar to obtain hexacarboxyl binuclear phthalocyanine iron.
[0008] The hexacarboxyl binuclear metal phthalocyanine iron catalyst of the present invention is characterized in that it is prepared by the above method. Two phthalocyanine units in the hexacarboxyl binuclear metal phthalocyanine iron catalyst share a benzene ring, so that it has a larger π electron conjugated system and the catalytic oxidation activity is improved.
[0009] The hexacarboxy binuclear metal phthalocyanine iron catalyst of the present invention is used for activating permonosulfate to degrade levofloxacin pollutants in water environment, and is characterized by: adding 50mL, 20mg / L levofloxacin pollutant solution and hexacarboxy binuclear metal phthalocyanine iron catalyst into a reaction container, wherein the concentration of the hexacarboxy binuclear metal phthalocyanine iron catalyst after addition is 0.4g / L, the initial pH of the mixed system is 6.5, and then adding permonosulfate (PMS) to start the reaction, wherein the concentration of the permonosulfate after addition is 1mM, and the degradation rate of ofloxacin reaches 99% within 5 minutes.
[0010] Compared with the prior art, the present invention has the following advantages and beneficial effects: 1. The present invention adopts the phthalic anhydride urea melting method to prepare hexacarboxyl binuclear metal phthalocyanine iron, thereby expanding the π conjugated system of the metal phthalocyanine and improving its catalytic activity.
[0011] 2. The hexacarboxyl binuclear metal phthalocyanine iron prepared by the present invention has good catalytic activity and can resist the interference of inorganic anions and complex organic matter in water.
[0012] 3. The hexacarboxyl binuclear metal phthalocyanine iron activated PMS system prepared by the present invention degrades pollutants mainly by generating high-valent metal oxygen species, which plays a leading role in the degradation process of pollutants. BRIEF DESCRIPTION OF THE DRAWINGS
[0013] Figure 1 This is the Fourier transform infrared spectrum of the prepared hexacarboxy binuclear metal phthalocyanine iron.
[0014] Figure 2This is a comparison chart of the degradation rates of LVF by the prepared hexacarboxy binuclear phthalocyanine iron and tetracarboxy mononuclear phthalocyanine iron. DETAILED DESCRIPTION
[0015] The above contents of the present invention are further described in detail below through examples, but this should not be understood as the scope of the above subject matter of the present invention being limited to the following examples, and all technologies implemented based on the above contents of the present invention belong to the scope of the present invention. Example 1
[0016] Step S1, preparation of hexacarboxamide binuclear phthalocyanine iron: weigh 5.76g of trimellitic anhydride, 1.09g of pyromellitic anhydride, 18g of urea, 2.18g of ferrous chloride and 0.27g of catalyst ammonium molybdate tetrahydrate, grind and mix them evenly in a mortar and transfer them to a 100mL crucible, place the crucible in a 250mL glass beaker to prevent the ammonia generated during the reaction from splashing the raw materials, and then place the crucible in a muffle furnace for heating reaction. The heating reaction process adopts a two-stage heating method. First, the temperature is raised to 145°C within 40min, the crucible is taken out and shaken to mix the materials evenly, and then placed in a muffle furnace for constant temperature reaction at 145°C 30min, then raise the temperature to 200℃ within 55min and react at a constant temperature for 4h. After the reaction is completed, cool to room temperature, grind the product in an agate mortar to obtain a solid powder, add the solid powder into a 250mL three-necked round-bottom flask, add ultrapure water, heat and reflux at 100℃ in an oil bath for 1h, centrifuge the mixture to remove the supernatant, wash twice with ultrapure water, then wash twice with 2wt% hydrochloric acid solution in the same process, wash with ultrapure water until neutral, finally wash twice with acetone and anhydrous ethanol according to the above operation, then place in a vacuum drying oven for 12h, and grind with an agate mortar to obtain hexamethylamide binuclear phthalocyanine iron after cooling; Step S2, preparation of hexacarboxyl binuclear phthalocyanine iron: add the hexacarboxamide binuclear phthalocyanine iron obtained in step S1 to a 250mL three-necked flask, add 100mL of 2mol / L NaOH solution, stir under magnetic force in an oil bath for reflux reaction for 12h, add 5 times of ultrapure water dilution after the reaction, centrifuge, take the supernatant, adjust the pH to 1-2 with concentrated hydrochloric acid solution to produce phthalocyanine iron floccules, stand for 12h to precipitate the phthalocyanine iron, pour out the upper clear liquid, centrifuge the lower material, wash with ultrapure water continuously to neutrality during the centrifugation process, wash with methanol, acetone and anhydrous ethanol in turn under the same operation, repeat three times, finally place it in a vacuum drying oven at 80°C for 10h, take out the sample after the sample is cooled to room temperature, grind it evenly in an agate mortar to obtain hexacarboxyl binuclear phthalocyanine iron. Fourier transform infrared spectroscopy was used to characterize the surface functional groups of the catalyst.
[0017] Step S3, add 50mL, 20mg / L levofloxacin pollutant solution and hexacarboxyl binuclear metal phthalocyanine iron catalyst to a 100mL beaker, wherein the concentration of the hexacarboxyl binuclear metal phthalocyanine iron catalyst after addition is 0.4g / L, the initial pH of the mixed system is 6.5, then add PMS to start the reaction, wherein the concentration of PMS after addition is 1mM, take a certain amount of solution at intervals, filter through a 0.22μm polyethersulfone membrane, and immediately mix 900μL of the filtrate with 100μL of 0.1M Na2S2O3 solution to terminate the reaction. The degradation rate of ofloxacin reaches 99% within 5min. Example 2
[0018] As described in Example 1, except that the quencher in step S3 is 100 mM ethanol solution, steps S1 and S2 are the same as in Example 1, and the degradation rate of LVF is 99%.
[0019] The above embodiments describe the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The above embodiments and descriptions are only for illustrating the principles of the present invention. Without departing from the scope of the principles of the present invention, the present invention may have various changes and improvements, and these changes and improvements all fall within the scope of protection of the present invention.
Claims
1. A method for preparing a hexacarboxyl binuclear metal phthalocyanine iron catalyst, characterized in that The specific process is: Step S1, preparation of hexacarboxamide binuclear phthalocyanine iron: trimellitic anhydride, pyromellitic anhydride, urea, ferrous chloride and catalyst ammonium molybdate tetrahydrate are ground and mixed evenly, and then the mixture is heated to 140-150° C. and reacted at a constant temperature for 20-40 min, and then the mixture is heated to 200-210° C. and reacted at a constant temperature for 3-5 h. After the reaction is completed, the mixture is cooled to room temperature, and the product is ground into fine powder to obtain hexacarboxamide binuclear phthalocyanine iron; Step S2, preparation of hexacarboxyl binuclear phthalocyanine iron: adding the hexacarboxyl amide binuclear phthalocyanine iron obtained in step S1 into a reaction container, then adding NaOH solution and stirring and refluxing the reaction, adding ultrapure water to dilute after the reaction is completed, centrifuging, taking the supernatant and adjusting the pH to 1-2 with concentrated hydrochloric acid to produce phthalocyanine iron floccules, and standing the phthalocyanine iron to precipitate to obtain hexacarboxyl binuclear phthalocyanine iron.
2. The method for preparing the hexacarboxyl binuclear metal phthalocyanine iron catalyst according to claim 1, characterized in that The specific steps are: Step S1, preparation of hexacarboxamide binuclear phthalocyanine iron: weigh 5.76g of trimellitic anhydride, 1.09g of pyromellitic anhydride, 18g of urea, 2.18g of ferrous chloride and 0.27g of catalyst ammonium molybdate tetrahydrate, grind and mix them evenly in a mortar and transfer them to a 100mL crucible, place the crucible in a 250mL glass beaker to prevent the ammonia generated during the reaction from splashing the raw materials, and then place the crucible in a muffle furnace for heating reaction. The heating reaction process adopts a two-stage heating method. First, the temperature is raised to 145°C within 40min, the crucible is taken out and shaken to mix the materials evenly, and then placed in a muffle furnace for constant temperature reaction at 145°C 30min, then raise the temperature to 200℃ within 55min and react at a constant temperature for 4h. After the reaction is completed, cool to room temperature, grind the product in an agate mortar to obtain a solid powder, add the solid powder into a 250mL three-necked round-bottom flask, add ultrapure water, heat and reflux at 100℃ in an oil bath for 1h, centrifuge the mixture to remove the supernatant, wash twice with ultrapure water, then wash twice with 2wt% hydrochloric acid solution in the same process, wash with ultrapure water until neutral, finally wash twice with acetone and anhydrous ethanol according to the above operation, then dry in a vacuum drying oven for 12h, and grind with an agate mortar to obtain hexamethylamide binuclear phthalocyanine iron after cooling; Step S2, preparation of hexacarboxyl binuclear phthalocyanine iron: add the hexacarboxamide binuclear phthalocyanine iron obtained in step S1 to a 250mL three-necked flask, then add 100mL of 2mol / L NaOH solution, and reflux under magnetic stirring in an oil bath for 12h. After the reaction, add 5 times of ultrapure water for dilution, centrifuge, take the supernatant, adjust the pH to 1-2 with concentrated hydrochloric acid solution to produce phthalocyanine iron floccules, let stand for 12h to precipitate the phthalocyanine iron, pour out the upper clear liquid, centrifuge the lower material, and continuously wash with ultrapure water until neutral during the centrifugation process. Wash with methanol, acetone and anhydrous ethanol in the same operation, repeat three times, and finally place it in a vacuum drying oven at 80°C for 10h, take out the sample after cooling to room temperature, and grind it evenly in an agate mortar to obtain hexacarboxyl binuclear phthalocyanine iron.
3. A hexacarboxyl binuclear metal phthalocyanine iron catalyst, characterized in that The catalyst is prepared by the method of claim 1 or 2. Two phthalocyanine units in the hexacarboxyl binuclear metal phthalocyanine iron catalyst share a benzene ring, so that the catalyst has a larger π electron conjugated system and has improved catalytic oxidation activity.
4. The hexacarboxyl binuclear metal phthalocyanine iron catalyst according to claim 3 is used to activate peroxymonosulfate to degrade levofloxacin pollutants in water environments.
5. The use according to claim 4, characterized in that: 50 mL of 20 mg / L levofloxacin pollutant solution and hexacarboxy binuclear metal phthalocyanine iron catalyst were added to the reaction container, wherein the concentration of the hexacarboxy binuclear metal phthalocyanine iron catalyst after addition was 0.4 g / L, and the initial pH of the mixed system was 6.
5. Permonosulfate (PMS) was then added to start the reaction, wherein the concentration of permonosulfate after addition was 1 mM. The degradation rate of ofloxacin reached 99% within 5 minutes.